Pre-Existing Diabetes and Prediabetes in Pregnancy: Evaluation on Glycaemic Control, Pregnancy Outcomes and Clinical...

Women with pre-existing diabetes remain at increased risks of adverse pregnancy complications. Optimising glycaemic control before and during pregnancy could reduce risk but data from Asian countries are limited. This study evaluates maternal glycaemia, management strategies and pregnancy outcomes in women with diabetes in a multiethnic cohort.

We retrospectively studied pregnancies with pre-existing diabetes or prediabetes at a Singapore tertiary hospital from 01/01/2022 to 31/12/2024. Maternal data and pregnancy outcomes were analysed by diabetes subtype. Multivariate logistic regression identified factors linked to adverse outcomes, including fetal overgrowth (macrosomia and large-for-gestational-age [LGA]) using local birthweight standards.

Of 289 pregnancies (75.8% Type 2 diabetes mellitus [T2DM], 19.0% prediabetes, 5.2% Type 1 diabetes mellitus [T1DM]), median maternal age was 33 years and pre-pregnancy body mass index (BMI) was 29.3 kg/m². HbA1c improved from 7.0% to 6.1% across trimesters (p < 0.00). Macrosomia (≥ 4 kg) occurred in 4.2% of infants, while preterm birth was more frequent in T1DM (33.3%) than in T2DM (5.0%) or prediabetes (1.8%). Retinopathy screening was completed in 67.6% of patients and continuous glucose monitoring (CGM) or pump devices were not utilised. Using Singapore LGA reference, third trimester HbA1c < 6.5% was associated with lower odds of LGA.

Multidisciplinary care enhanced glycaemic control and reduced macrosomia, but women with T1DM remain at increased risk of preterm delivery and neonatal morbidity. Enhanced preconception care, retinopathy screening and adoption of real-time CGM may improve outcomes in Asian women with pre-existing diabetes in pregnancy.